In the industry concerned with packing smaller objects such as tubes, bottles and the like in carton boxes, there is a constant need to increase the productivity of the packing machines. One aspect of a packing machine is the number of units that the machine can handle during a specific time interval. There are different ways of achieving a higher throughput in such a machine. One way is to reduce the cycle time for each object, i.e. to allow more objects to pass the machine during the same time interval. Such a solution is often difficult to achieve since it may involve a redesign of the machine and at some point, it is not possible to reduce the cycle time for a specific operation. Another way to increase the throughput in a production line is to use several parallel machines, at least for some operations. Such a solution requires more space and is not as cost-effective, but may be a possibility when an older production line is to be upgrades.
One type of machine that there may be a need to improve is the machine that pick up pre-glued folded paper cartons, erects them and feeds them to a conveyor track. On the conveyor track, the cartons continue to the next station, in which a tube or the like is inserted into the carton, with or without an instruction leaflet. The side flaps of the carton is then folded and the carton is closed, eventually also sealed, and packed in larger shipping units.
EP 1594745 B1 describes a carton manipulation and feeder apparatus, which is adapted to pick up folded, pre-glued cartons from a hopper, erects them and to feed them to a conveyor track. The cartons are erected to a square shape and are inserted at the infeed end of the conveyor track. The cartons are inserted between lugs attached to the conveyor track and having a distance between them that corresponds to the width of the carton to be inserted. In order to be able to feed the carton to the conveyor track, the carton is inserted at the infeed end of the conveyor track, where the conveyor chain changes direction and is conveyed on a wheel. In this end region of the conveyor track, the lugs are angled apart due to the conveyor wheel, which allows the erected cartons to be inserted between the lugs. When the carton is inserted and the chain has moved somewhat, the lugs will be perpendicular to the conveyor chain again and will hold the carton in position.
EP 0800450 B1 describes another carton transfer assembly adapted to transfer folded cartons from a hopper, open them and transfer them to a conveyor. The cartons are opened by an extensible rod. The opened cartons are inserted in carton pockets provided between chain lugs. The length of the carton pocket is longer than the carton itself, thereby allowing the opened carton to be inserted into the carton pocket during the rotation of the rotary feeder.
U.S. Pat. No. 7,328,561 B2 describes an apparatus for erecting boxes and setting them on a conveyor. The apparatus pick up folded boxes from a magazine, erects them and inserts them into conveyor cells on a conveyor track. The cartons are erected to a square shape by an erecting element and are inserted at the infeed end of the conveyor track. The cartons are inserted between lugs attached to the conveyor track and having a distance between them that corresponds to the width of the carton to be inserted. In order to be able to feed the carton to the conveyor track, the carton is inserted at the infeed end of the conveyor track, where the conveyor chain changes direction and is conveyed on a wheel. In this end region of the conveyor track, the lugs are angled apart due to the conveyor wheel, which allows the erected cartons to be inserted between the lugs. When the carton is inserted and the chain has moved somewhat, the lugs will be perpendicular to the conveyor chain again and will hold the carton in position. The height of the rear lug is substantially lower than the front lug in order to facilitate the insertion of the box. This requires two lugs for each box.
U.S. Pat. No. 5,573,490 describes an apparatus for erecting a folding box and folding its closure tabs before it is transferred into a conveyor device. The insertion of the erected boxes into the conveyor device is not described.
U.S. Pat. No. 4,331,436 describes a device for erecting and counter collapsing boxes from preformed blanks. The erected box may then be fed to a conveyor belt having compartment dividers adapted to hold the boxes. The boxes enter at the infeed end of the conveyor belt, where the conveyor belt changes direction and is conveyed on a wheel. In this end region of the conveyor belt, the compartment dividers are angled apart due to the conveyor wheel, which allows the erected boxes to enter between the compartment dividers.
EP 0331325 B1 describes a rotary transfer mechanism which is adapted to pick flat, collapsed cartons from a magazine. The cartons are picked from the magazine by a pick head having suctions cups. The cartons may open slightly during the removal from the magazine, but the cartons are substantially in their collapsed condition when the insertion of the carton into the conveyor begins. During the insertion, the leading corner hits a leading flight of the conveyor and since the pick head moves faster than the conveyor, the carton is pulled against the leading flight of the conveyor and is thus pulled open. In this way, a folded carton can be inserted between two parallel flights of the conveyor. There are several problems associated with this solution. One problem is that the carton is driven into the leading flight and is pulled against the leading flight during the opening of the carton. This will put a great deal of strain on the carton, which may lead to damages to the outer surfaces of the carton. Since the distance over which the carton is opened is relatively short, the strain on the carton is further increased. A further disadvantage may be to handle cartons in which residual glue inside the carton causes the sides of the carton to stick to each other. Such a carton may be further damaged during the opening and may also disrupt the insertion of further cartons.
These solutions may work well for some applications, but may be inflexible, especially when the throughput of the system is to be increased. There is thus room for improvements.